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2008 FEH Autoclimate HVAC Issue A.K.A. "The Perfect Storm"

Hi there hybrid groupies, I am new to this site but have been a owner of a 2008 FEH for almost a year now. I just discovered this site/forum and have read some interesting and informative posts and learned that GaryG really knows his stuff! I originally purchased '08 FEH in June '07. I have put about 20K on the vehicle already and while the FE seems to improve in stair steps (much better than first driving off the lot)... I am encountering a HVAC issue that I am wondering of anybody else has experienced...

Since about 12K and during the (Florida) winter I noticed that the dual climate control now standard on the FEH started to malfunction. What I noticed while on a interstate trip up to Gainesville is that the passenger side of the vehicle was blowing much warmer than the driver's side. For those that don't have the '08 model FEH; there are themostat dials on both the driver's and passengers side that let you set the temperature to the exact degree. You also have the option of disengaging the passenger's side and control both through just the driver's side. What is happening is that basically anytime I try to set the temperature in my "goldilocks zone" between 73-76 degrees F, the passenger's side blows much warmer (85 deg +) depending on the outside temperature. My driver's side autoclimate tries to overcompensate for the hot air by blowing much colder than the set 75 degrees creating the perfect storm scenario within the cabin of my FEH. As you can imgaine this does not bode well with the better half since she she is usually the one sitting in the passenger's seat receiving the hot air... and let me tell you gentleman I now have been informed that mascara does not apply well at those temperatures . With this new found motivation, I have set out to get to the bottom of this issue... while still under warranty! Through investigation I have come up with the following observations/conclusions:

1. It does not appear to be an issue with the AC's ability to create cold air. If you force the issue by turning the passenger's side to 70 deg of lower, the air blows quite cold.

2. An offset of 75 deg/drivers side and 70 deg/passengers side seem to provide some balance.

3. The variance is more severe when the temperature outside is cold and you are using the autoclimate to warm the cabin (AC not activated).

4. The temperature seems to balance out better when in EV mode and the compressor shuts off. This observation seems like a good clue for paring down the possible problems.

When I took the vehicle in for it's 20K service to my friendly Ford dealer (yep, they talked me into the plan) I told them about the issue. Three weeks and two visits later I have had the ventilation doors electronically recalibrated, a new HVAC electronic face put in and the problem still exists. I've apparently got the local Ford mechanics and the Ford hotline folks srcatching their heads. I half seriously suggested them shipping my FEH back to the factory at Kansas City to get it fixed. I don't think they liked my idea. They give me my vehicle back and told me they they need to wait until they can get ahold of another FEH to do comparative testing. By the looks of the demand, I think I'll be waiting a while! I guess I should just be glad that I haven't had one of the horrific total power loss problems I have read on this site (knock on wood).

While I am not chipper about it, I can live with my perfect storm. I guess I just expect more from a brand new vehicle. thought I might see if anybody has experienced similar problems or has any suggestions. Comments appreciated

Thanks for the support

Thanks for the support Evlar, and as you know, my FEH has a manual control A/C. My repair manuals are for the '05 FEH, so research will have to wait till I get a set of '09 FEH/MMH manuals which are not available yet.

It just so happens I'm having the same problem in my '02 EB Explorer since I had the compressor replaced. With 84,000 miles, I had the A/C compressor clutch go bad and lost cooling this winter for about 2 weeks. After the repair was made, Autoclimate didn't blow at the fast fan speed it had when you first start the vehicle. The air wasn't as cold on both sides as it had been in the past. I had used a friend of a friend's shop to do the repair (not a dealer), so I called him. He said it sounded like they may not have got the exact amount of R-134a in the system and for me to bring it back.

A few days later when I was going to take it back, it started working fine. With the temperature changing to cold and hot again here in Florida, we notice the passenger side was blowing much warmer air than the drivers side after the weather got warm again. It has been 2 month since I had the compressor changed now, and think the system may have in fact not had the proper charge. The problem is the rear A/C seems to blow cooler air than the front passenger side also.

This is what I think is the possible problems:

You and I don't have the correct high and low R-134a levels, and the heater core ductwork treats the passenger side with warmer air. Your A/C system could have a very slow leak, and my system might have not got the right balance after being recharged. Other than that, the blend doors are not operating properly in the ductwork. More than likely the autoclimate systems are controlled by the PCM through sensors. If we don't have the correct levels of R-134a, the PCM may sense incorrect information and adjust the blend doors incorrectly. In the manual A/C system, the workshop manual stresses problems could be a result in incorrect levels of R-134a.

On my '05 FEH, I did a heater core bypass to keep the cooler air in the cabin longer while in EV. It didn't get cold enough for me to hook the heater core back up this winter. Most likely I will do a heater core bypass on the '09 when I get it.

Thanks Gary. You bring up an

Thanks Gary. You bring up an interesting, yet simple possibility with the R-134a levels and/or leak. I admit I have a limited understanding of the full HVAC system and it's entire components (very complex these days from an electrical standpoint), however one would tend to gravitate toward a software/electrical issue being that it is a new car and I think that is what the folks at Ford have been focusing on. I think I would be lucky if it were only a level of R-134a. Not so lucky if it is a leak.

In your experience, is there any visual evidence around the compressor or compressor lines that would illustrate a R-134a leak? If you have any revalations on that Explorer of yours, please let me know. On a side note, I see billionaire entrepreneur Kerkorian offered to buy another 20 million Ford shares today to help our ailing automaker. Maybe they can now get moving on improving on their fleet! Esp the hybrids.

Ok Evlar
I called the shop

Ok Evlar

I called the shop that replaced my A/C compressor and discussed both our problems with the right side blowing warmer. He said it could be a sensor, but said the basic rules are to check the R-134a levels first to rule that out. He wants me to bring my Explorer in this Thursday and he would do some research on possible other sources that could be the problem in the mean time. I'm dealing with the owner of the shop and he seems real sharp. It's starting to get hot here in SO FL so I'm determined to get the problem solved right away.

With very slow leaks, it's hard to locate the location sometimes. The FEH/MMH not only has the cabin A/C, but that aux A/C for the HV battery. Most of the time techs use meters to detect and locate leaks and there are chemicals that glow that are added to the system for visual inspections. It sounds to me that the first thing the dealer tech and the Ford hotline people should have done was check the high and low pressures of the R-134a levels first before replacing parts on your vehicle. Ambient temperatures and relative Humidity affect refrigerant normal discharge pressures and normal suction pressures test according to the manuals. Since my A/C was working fine before the compressor clutch went bad, I tend to lean that two problems didn't start at the same time with a sensor also.

Have you seen the chemicals

Have you seen the chemicals work?

The chemical will spray on adjecent equiment, similar how a fire spreads from a source of ignition. Then they use an ultravilolet light to see where the source of the spray is. Then they just hose the spray off and fix the leak.

Evlar, the shop added 1/2

Evlar, the shop added 1/2 pound of R134a today and both the right side and the left side are within 2 degrees now. It seems it's working like it always has with only the 2 degrees lower being on the far right duct. The center ducts are much closer to the same, which was not the case before the additional of 1/2 pound of R134a.

My tech said it could be the sensor or low R134a, but mine was clearly low R134a. In my case, the clutch could have caused my compressor to lose a little R134a before they recovered the R134a and added it back to the system after the compressor was replaced. At any rate, the system was low which caused the right ducts to blow warmer air.

You may want to take your vehicle to another dealer that understands a dual A/C in a FEH/MMH which has the aux battery A/C. These techs get a fixed amount of $ hours on a job like this, so its sounds like your tech can't locate the leak. If he adds R134a, this means he knows there is a leak and has to fix it. My guess is he knows there is a leak (maybe in the Aux system connections) that will cost him more hours to locate than the job will allow under warranty work.

The reason I now think this is the problem is mine was repaired and your jerk wants to wait to check out other vehicles. That is pure BS in my opinion. If the tech talked to the Hot line, he told them the system was full to get extra hours on the parts he replaced.

Thanks Gary. I think at the

Thanks Gary. I think at the very least I will look into this further on my own. If I haven't heard back from the local Ford service folks within two weeks, I will call them and persist. I will NOT stand by while my warrany fizzles away and they do nothing else to fix the problem. Thing is, I know if I go too aggresive on these guys, they'll totally shut down. That is a last resort in my mind. Like you said, it's starting to get very hot in SFL... so I need to figure out what is going on.

On another note... I just filled up at the pump yesterday and my fuel gauge has started malfunctioning! I was thinking... you've got to be kidding! I completely topped off the tank and the gauge only raised to 2/3 a tank. The "miles to empty" also reflected the 2/3 tank. Interestingly enough, it has slowly started to creep up and the miles have been adjusting... but it is still not reflecting a full tank yet. I find myself curious as to what might have caused this. I did fill up with that 90/10 ethanol blend (I try to avoid it when possible), but would be surprised if that is the cause.

Oh well, I guess I have another reason to call the Ford folks again to bring the vehicle in. I take very good care of my FEH, so I am guessing that my luck is just bad. Thanks again for the advice!